Field of the Invention
The present invention relates to an antenna cover, and in particular to an antenna cover of a horn antenna module.
Description of the Related Art
Conventionally, the free end of a waveguide of a horn antenna is covered by an antenna cover. The antenna cover prevents water from entering the wave guide, and prevents the convertor of the horn antenna from being damaged by water.
Conventional antenna covers are planar, and are made of materials that have a low dielectric coefficient (for example, polypropylene). However, when the environmental temperature changes, the difference between environmental pressure and the inner pressure of the horn antenna deforms the planar antenna cover. The performance (such as cross polarization) of the horn antenna is affected, and the signal transmission of the horn antenna deteriorates.
Conventionally, an antenna cover with one single protrusion is provided to increase the strength of the antenna cover, and to prevent deformation. However, the antenna cover with a single protrusion cannot optimize the signal transmission of each horn antenna on the horn antenna module (for example, one horn antenna module may have one low-band horn antenna and two high-band horn antennae). In particular, the performance of the horn antennas located on lateral sides of the horn antenna module may become deteriorated.